Tank heater



Oct. 2 1950 B. B. BOSWORTH TANK HEATER Filed Feb. 26, 1947 Patented Oct. 24, 1950 UNITED STATES PATENT I OFFICE 12 Claims.

This invention pertains to thermal control of the walls of containers, and more particularly to a heater apparatus for warming the contents of water closet tanks, and other containers, for automatic prevention of condensation of moisture from the surrounding air on the exterior of walls thereof, and consequent dripping of condensate. I

This condition is more or less prevalent in localities where the water supplied to closet tanks is of low temperature, less than that of ordinary room temperature. 1 This condition is most common in instances wherein the water is supplied from a private source or from a relatively deep well. As result the tank walls are chilled, or their temperature decreased, and the entrained moisture content of adjacent humid air contacting the cooled tank walls, particularly of a conventional water closet tank, is condensed thereon, and drains down such cold wall and drips upon the floor.

Such condensation can be prevented by warming the contents of the tank to maintain the temperature of the tank Walls above the dew point at which precipitation or condensation of moisture occurs. Such tanks are ordinarily supplied through automatic valves which control the quantity of water supplied and arrest the supply when raised to a predetermined level. It is obvious that the cold water admitted can not be sufilciently warmed as rapidly as supplied.

In the present invention there is contemplated a water heater which will be automatically started upon the admission of a fresh supply of water, but its deenergization will be delayed until the water reaches a predetermined temperature. Obviously when the temperature of the water within a tank has once been brought to or above the surrounding room temperature, that of the water content will not ordinarily fall there below, even after a long period of time.

The object of the invention is to simplify the structure, as well as the means and mode of operation of automatic temperature control means for water tanks, or the like, which may not only be economically constructed, but will be efiicient in use, automatic in operation, uniform in action, having minimum number of working parts, and be unlikely to get out of repair.

A further object of the invention is to provide a thermal control apparatus for water tanks 1 which may be easily and quickly installed by an A further object of the invention is to provide 2 means for automatically maintaining the water heating apparatus in continuing operation until the temperature has been raised to a predetermined degree, regardless of the length of time required, and then effect instant discontinuation thereof.

A further object of the invention is to provide a thermal control apparatus for Water tanks, possessing the advantageous structural features, the inherent meritorious characteristics, and the mode of operation herein described, or' their equivalents.

With the above primary and other incidental objects in view aswill more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the m'ode'of operation, as hereinafter described or illustrated in the accompanying drawings or their equivalents.

In the drawings, wherein is illustrated the preferred, but not necessarily the only form of embodiment of the invention, Fig. 1 is a side elevation of a thermal control apparatus embodying the present invention while the water heater is energized, mounted on a fragmentary portion of a water tank.

Fig. 2 is a front elevation of the thermal control apparatus in the condition shown in Fig. 1.

Fig. 3 is a further side elevation of the same apparatus,'partly broken away, after its automatic operation to deenergize the water heater.

Fig. 4 is adetail view of a conventional thermal responsive switch or valve operator.

Like parts are indicated by similar characters of reference throughout the several views.

While the present apparatus is primarily intended for controlling the temperature of the contents of conventional water closet tanks, for prevention of: moisture condensation on the exterior walls thereof and consequent drippage, it is obvious that it may be applied to various other tanks and containers; as for example, warming stock watering troughs, the temperature control of contents of bath tubs, chemical mixtures, and various other: purposes. Therefore it is not intended that the scope and application of the invention shall be unduly restricted to those herein shown and described, for illustrative purposes, but shall be deemed applicable to other uses and purposes, and to include other embodiments.

, Referring to the drawings, l indicates portions of the side and bottom walls of a conventional water tank to which a quantity of cold water is intermittently admitted. Suspended from the top "temperature. walls I ofthe tankare maintained at or slightly above the surrounding atmospheric temperature.

margin of the side wall I of the tank is a bracket 2, preferably of non-electro conductive material, but which may be a metal bracket from which the various electrically connected elements are individually insulated. The bracket is detachably engaged over the margin of the tank wall I by a hanger hook 3. Pivotally mounted upon a supporting arm 4 attached to the bracket 2 is an cillatory float arm 5, carrying at its extremity a float 6 which may be of any suitable type or shape.

Attached to the opposite, or pivotal end, of the float arm '5 is a cam or eccentric 'I which oscillates in unison with the float arm. Mounted on a stud B projecting from the bracket 2 is a contact arm 9, which may be yieldingly orresiliently mounted for make and break contact engagement with a companion stationary contact In so long as the float remains in its down position of Figs. 1 and 2, and the cam I retracted. The electrical contacts 9 and i0 control an electrical circuit lll l leading from power supply lines l2'to a conventional electrical submersion heater-l3 immersedwithin. the-.water content of the tank I.' As the waterv is exhausted from the tank I the float 6 descends with thewater level,

"causing the float arm 5 toturn' the cam or eccentric I to theposition shown in Figs. 1 and 2, wherein the contactsarm'fiis permitted to descend into-engagement with the companion contact ID to close thecircuit l Il l" and thusenergize the electrical heater l3. As the tank refills with cold water, which ordinarily. occursxauto- -matically, the float arm 5 is held down by a thermostatic detent-blade l4; and. the heater1l3 continues to be energized. :The-Idetent blade I4 is atached to the'oscillatory: floatarm 5, and the free'end l5 thereof-temporarily engages beneath a plate or ledge l6 projecting from the supporting bracket 2.- The thermostatic-detent blade 1 l4 continues to hold the float arm depressed and the 0am I in position to permit the contact arm 9 to continue in engagement with-the contact Ill to maintain the heater unit. [3 energized, until the temperature. of thefresnwater supply is again raised to a predetermined degree. equal to, or

slightlyabove, that of the surrounding room Quite naturally, so long as the incident to the warm condition of the water therein no moisture condensation will occur on 'the exterior or the walls I of the tank, prevention of which is the primary objective of the instant invention.

It is obvious that Ithecdominating conception -of the instant invention'. may. be variously embodied.- Forexample in-lieu of-the floatlever operation switch illustrated, a conventional subployed. In suchinstallation, atube .11 having at one end a bulb-l8 submerged in; the water, is filled with a thermally. expansive and contractive fluid, which controls a communicating bellows 01' sylphon l9 above the level of the water. The expansion and contraction of the bellows or -sylphon [9, in accordance with fluctuations of heater, as for example a gas burner or hydrocarnbon fuel burner having apilotlight; A thermox static valve control element such as indicated in mersion type thermostatic electric switch oper ator of the type illustrated in Fig. 4 may be em- Fig. 4 may be utilized to open and close a fluid supply valve to regulate the operation of such exterior burner. This is one of those instances wherein the problem having been recognized and its solution visualized, upon disclosure of its conception, many manners of utilizing existing structures for accomplishment of the desired result, will readily occur to the mind of an ingenious mechanic. Hence the invention is not limited to the specific embodiment shown.

- In the structure as illustrated in the drawings, the detent blade [4 is of spring tension. As the float arm 5 reaches the limit of its range of descent, the cam head I is turned to a position to permit the descent of the contact 9 into engagement with the stationary contact [0 to energize the heater 13. In such position of the float arm 5, the spring detent blade l4, under inherent tension of the blade will project its free end l5 beneath the stop plate l6, and so temporarily lock the floatarm and cam head I in their retractecl inoperative positions maintaining the heater l3 energized. In the meantime the tank may continue to fill with cold-water. When the temperatureof the contents of the tank has been raised sufficiently to warm the exterior surfaces thereof to a predetermined temperature, equal to or slightly above that .of the dew pointof the surrounding atmosphere, the. detent blade l4 whichis of substantiallyu shape, and of bimetallic thermostatic material, will respond :to the increased temperature of the water in which it is submerged, and will-expand sufiicientlyto disengage theend 15 of the detent blade 14 from under the stop plate l6; -Thereupon the buoyancy of the'float i will immediately elevate the float arm 5 and partially turn .the camhead 1,

shows a thermostatic unit comprising the tubular stem [1- having a terminal bulb .I8 filled with thermally expansive fluid expands a sylphon 5 I9 to oscillate avalve operatinglever 20 toshut off a valve 2| controlling a fuel supply conduit 22 leading to a heater burner exteriorly of the tank. Obviously the thermostatic unit shown in Fig. 4 might be utilized to control the contacts 9 lll of circuit l i-l I controlling the electrical heater l3, thereby eliminating the float arm and cam head. Such modified thermostatic apparatus might likewise be utilized to control aconventional electrically actuated valve 2| to regulate a fuel supply through the conduit 22.

From the above description it will be apparent that there is thus provided adevice of the character' described possessing the 1 particular. features of advantage before enumerated as desirable, but which obviously susceptible of modification in its form, propo rtions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

.While in order to comply with the statute the invention hasbeen described in language more or less specific as to structural features, it is to be understood that the-inventionis notllmited to the specific featuresshown, but thatthe means and construction herein disclosed comprise the preferred form of several modesv of putting the invention into effect, and the .inventionis therepended claims.

Having thus described my inventiong'I claim:

1. A means for minimizing thecondensation of moisture from surrounding atmosphere and resulting drip from exterior surfaces of tanks and containers, including an oscillatory float arm therein, a cam movable therewith, an electrically energized heater element submerged in the contents of the tank or container, an electrical energizing circuit therefor, a pair of make and break contacts included in the circuit, one of which is movable relative to the other contact in accordance with the fluctuations of the float arm to open and close the energizing electrical circuit, and a, thermally responsive detent member carried by the float arm and detachably engageable with a stop to temporarily maintain the float arm in circuit closing relation until released by the influence of increased temperature of the contents of the tank or container upon the thermally responsive detent member to permit movement of the float arm to effect opening of the make and break contact of the circuit to deenergize the heating element.-

2. A means for preventing condensation of moisture from surrounding atmosphere on the exterior surface of a water closet tank or the like, and resulting drainage of precipitation onto a floor, wherein the contents of the tank are intermittently discharged therefrom and a fresh supply of cold Water admitted, including a heater for warming the newly admitted water supply, control means for automatically initiating the operation of the heater upon discharge of the preceding charge of water and admission of a fresh charge thereto, a deferred action device for maintaining the heater in operation until the temperature of the newly supplied charge of water is warmed sufficiently to raise the exterior surfaces of the tank to a predetermined temperature suflicient to prevent condensation of moisture thereon, and means responsive to the increased temperature of the contents of the tank to effect deenergization of the heater.

3. A means for preventing condensation of moisture from surrounding atmosphere on the exterior surface of a water closet tank or the like, and resulting drainage of precipitation onto a floor, wherein the contents of the tank are intermittently discharged therefrom and a fresh supply of cold Water admitted, including a heater element for warming the newly admitted water supply, an electrical circuit controlling operation of the heater, a make and break contact in the circuit, an actuator effecting closing of the make and break contact substantially coincident with the admission of the fresh charge of cold water to the tank, to initiate operation of the heater, control means maintaining the make and break contact closed until the temperature of the newly admitted charge of Water is raised to a predetermined temperature and make and break contact release means responsive to the increased temperature of the water effective to open the circuit and terminate influence thereon of the heater.

l. An apparatus for minimizing the condensation of moisture from surrounding atmosphere upon the exterior of walls of a tank, including a submersion type electrical heater immersed within the contents of the tank, an oscillatory float arm pivoted therein, an electrical switch controlling the electrical heater, an energizing electrical circuit therefor, a make and break contact therein opened by the rise of the float arm incident to the elevation of the level of contents of the tank and closed by the descent of the float arm incident to lowering of the level of content, and a thermostatically controlled delayed action latch maintaining the make and break contact closed and the heater element energized for an appreciable time after the content level has been elevated. I

5. An apparatus for minimizing the condensation of moisture from surrounding atmosphere on the exterior of walls of a container, including a heater for the contents of the container, a float operated regulator for the heater responsive to fluctuations of the fluid level of the contents of the container, and a delayed action detent for the regulator maintaining the heater in operation through an extended period until the temperature of the exterior Walls of the container have been raised to a predetermined temperature suflicient to prevent condensation of moisture thereon.

6. A means for minimizing the condensation of moisture from surrounding atmosphere and resulting drip from exterior surfaces of tanks and containers, including a heater element, a float operated regulator which by its movement initiatesand terminates the influence of the heater, a delayed action detent for the float deferring the ,operation of the float to decrease the influence initiate and terminate the operation of the heater element, a detent for maintaining the regulator in condition to continue the heater element in operation until the temperature of the contents of the tank or container is raised to a predetermined temperature by which the exterior surfaces of the tank or container are warmed sufficiently to prevent condensation thereon of moisture from the surrounding atmosphere, and thermostatic means responsive to the increased temperature of said contents effective to terminate further operation of the heater unit.

8. An apparatus for minimizing the condensation of moisture from surrounding atmosphere upon the walls of a container and its drip therefrom, including a heater element for the contents of the container, a lever operated control mechanism for the heater, and thermostatic control means for the lever responsive to fluctuations of the temperature of the contents of the container whereby the temperature of the latter is maintained substantially constant at a predetermined degree sufiicient to prevent condensation of moisture from the surrounding atmosphere.

9. Means for minimizing the condensation of moisture from surrounding atmosphere upon exterior surfaces of a Water tank, and the subsequent drip of condensate upon a floor, including a heater for the contents of the tank, an electrical control circuit for the heater, a make and break contact for said circuit, a detent automatically maintaining the make and break contact closed and the heater energized, a thermostatic release for the detent responsive to the increased temperature of the contents of the tank enabling opening of the make and break contact and 'de- :energization of the heater, the 'constr'uction and arrangement being 'su'chthat'the temperature of the water content of the tank -'is raised sufficiently to warm the exterior surfaces of thetank to a predetermined degree sufiicient to prevent condensation thereon of moisture from thesu'rrounding atmosphere.

10. Means for minimizing the condensation of moisture from surrounding atmosphere updme'x- 'ter ior surfaces of a water tank, and the' sub'scquent drip of condensate upon a floor, includin a heater for the contents'of the tank,' a-'c'ontrol device for automatically initiating ar'id halting operation of the heatenand a, regulating-device forcontinuing the operation'of the heater until thetern perature of the contents of the'tank is raised to a predetermined degreesu'chthat the "temperature of the exterior surfaces of the tank is increased suificiently to prevent condense: tio'n of'inoisture thereon.

11. The herein described method or eliminating condensation upon the exterior of "water tanks and the objectionable dripping thereof, including energizing a heateruponreceiptofia new supply of' water Withinthe tank, t0the infiuence of which heaterthe new supply-owner is subjected and maintaining energization of the heater until'the-new supply of water is warmed toa predetermined temperature in excess of that at which condensation of moisture will take place.

12. The herein described method of eliminating objectionable condensation and drippage from the exterior of a water tank, including warming anincoming supply of water to a predetermined temperature in excess of that at which condensation of moisture will take'place, and thereafter halting the warming influence until the tank has been emptied and a new supply of water received.

BLAKE B. BOSWORTHi REFERENCES CITED The'following references are of record'in'the file'of this'patent:

UNITED STATES PATENTS 

